VLAGAS

Hi Guys, I just picked up an Aliens Extermination machine. I know this is probably not the right place and that this is more to do with the emulation of it, but until I do find a forum thought i'd post here to see if anyone can help. My issue is that player's 1 gun cross hair is laggy on the screen e.g. to move cross-hair across screen it is not smooth and jumps from position to position. Anyone know what could be causing this? Trying to re-calibrate the gun does not help. Hoping this isn't a major problem... Thanks in advance for any help.